Drying apparatus



June 23, 1931. A. E. JONSSON 1,811,356

DRYING APPARATUS Filed Feb. 14, 1929 /5 INVENTOR:

409 00s [/VQPJ finsson BY: 7A:

A ORNEYS Patented June 23, 1931 PATENT OFFICE AUGUSTIN'US EDVARDJONSSON, OF LIDINGO', SWEDEN DRYING APPARATUS Application filed February14, 1929, Serial No. 340,000, and in Sweden February 15, 1928.

The present invention relates vto an improvement in drying apparatus ofthe type described and claimed in my copending application Serial No.339,999, and which comprises a rotating or oscillating cylinder,provided with heating-bodies or units adapted to heat and distribute thematerial to be dried. The principal object of the invention is toprovide a drying apparatus of this character in which the heating unitsare provided with or have formed thereon ribs or projections spaced atsuitable distances from each other, the material being dried restingagainst said ribs or projections. By this construction said materialwill be prevented from contacting with the heating-bodies too closely,thus avoiding too rapid heat absorption.

The heating-bodies or units may consist of heating-casings or jackets,disposed on the cylinder and/or the ends thereof, but they may alsoconsist of special heating-units extending into the cylinder. These twoalternatives may be used simultaneously.

According to a further embodiment of the invention, the ribs orprojections may be constructed of a material which is of low heatconductivity or possessing heat-insulating properties. Again, the ribsor projections may have only their faces, which contact the material inquestion, provided or coated with a material of low conductivity orheat-insulating properties. These ribs or projections serve not only topreevnt the material from making too direct a thermal contact with theheating-bodies, but also to facilitate the removal of the vaporsexpelled from said material, for the reason that the ribs or projectionsform channels by means of which said vapors may more easily escape thanthrough the mass of the material being dried.

In the drawings accompanying this specification,

Fig. 1 is a fragmentary longitudinal sectional view through an apparatusembodying the features of the present invention;

Fig. 2 is a cross-section taken on the line II-II in Fig. 1;

Fig. 3 is a sectional view taken on the line 'IIIIII in Fig. 2;

Fig. 4 is a view similar to Fig. 2, illustrating a modified form of theinvention; and

Fig. 5 is a sectional view taken on the line VV in Fig. 4.

Referring first to Figs. 1-3, 1 designates a drying-cylinder, which ismounted to rotate in any suitable manner and may be given a rotating oran oscillatory movement by means of a suitable driving-device, known perse. The side and end walls of the cylinder are preferably ofdouble-walled construction thereby to form heating jackets 5. lVithinthe cylinder are disposed a plurality of hollow heat-ing units 4, saidunits communicating by means of pipes with the jackets 5. Aheating-fluid is conveyed to the heating units 4 by a pipe, not shown,and after having passed through and been cooled in the several heatingunits of the drying-cylinder, it is allowed to escape through a suitableoutlet. In order to obtain a rapid and efficient drying operation, avacuum may be created within the cylinder by means of a suitable vacuumpump, in a manner known per se. To carry and guide the inner free endsof the heating units 4, extending inwards, supports or columns 15 areplaced diametrically within the cylinder, said columns being providedwith flanges 16 upon which the ends of the heating units rest. Theheating units 4, and, if desired, also the inner surface of the cylinderwall, as well as the end wall are provided with ribs or projections 6,which form supports for the material being dried so as to prevent toostrong a heating of said material. Said ribs may for this purpose bemade integral with the heating units and the jackets, or they may beattached to them in any suitable manner, for instance by welding orriveting, in which case the ribs may consist of a material having a lowheat conductivity or having heat-insulating properties in order toprevent too strong a heating of the goods being dried.

According to the embodiment shown in Figs. 4 and 5, the ribs arepartially integral with the heating units and the outer portions 20thereof are of a material of low heat conductivity. To permit theportions 20 to be securely attached, the ribs 6 may be formed, forinstance with a pair of thin side flanges 21, between which the portions20 may be secured, as shown in Fig. 5. 3

Having thus described my invention, what I claim is 1. A dryingapparatus comprising in combination with a rotatable cylinder, aplurality of hollow flat heating shelves extending through the wholelength of the cylinderand grouped in parallel on both sides of a freespace extending diametrically through the axis of the cylinderperpendicular to the plane of the shelves, each of said shelves ex--tending from the circumference of the cylinder to said diametrical freespace, said space communicating with the feeding and dis chargingopenings in the wall of the cylinder, said fiat shelves having aplurality of ribs disposed in embracing relation to the exterior of theheating shelves and extending per- 1 pendicular to the axis of thecylinder thereby to prevent the material being dried from coming intodirect contact with the walls of the thereby to prevent the materialbeing dried from coming into direct contact with the walls of theshelves, said ribs being formed of a material of low heat conductivity.

communicating with the feeding and discharging opening in the wall ofthe cylinder, said shelves having a. plurality of ribs disposed inembracing relation to the exterior of the plane heating shelves andextending perpendicular to the axis of the cylinder thereby to preventthematerial being dried from coming into direct Contact with the wallsof the, shelves, those surfaces of the ribs which are in contact withthe material to be dried'bein'g-coated with a material having a low heatconductivity.

5. A drying apparatus comprising in combination with a rotatablecylinder, a plurality of hollow plane heating shelves extending throughthe whole length of the cylinder and grouped in parallel on both sidesof a space extending in'a' diametrical plane perpendicular to the'planeof theshelves and communicating with the feeding and discharging openingin the wall of the cylinder, said shelves having a plurality of ribsdisposed in embracing relation to the exterior of V the plane heatingshelves and extending perpendicular to the axis of the cylinder therebyto prevent the material being dried from coming into direct contact withvthe. walls. of the shelves, those surfaces of the ribswhich are incontact with. the material to be dried being coated with aheat-insulating material. -AUGUSTINUS EDVARD JONSSON.

3. A drying apparatus comprising in com--.

bination with a rotatable cylinder, a plurality of hollow plane heatingshelvesextend ing through the whole length of the cylinder and groupedin parallel on bothsides of a space extending in a diametrical planeperpendicular to the plane of the shelves and communicating with thefeeding and discharging opening in the wall of the cylinder, saidshelves having a plurality of ribs disposed in embracing relation to theexterior of the plane heating shelves and extending perpendicular to theaxis of the cylinder thereby to prevent thematerial-being dried from Icoming into direct contact with the Walls "of the shelves, said ribsbeing formed of a heat insulating material.

4. A drying apparatus comprising in com-.

bination with a rotatable cylinder, a plurality of hollow plane heatingshelves extending through the whole length of the cylinder and groupedin parallel on both sides of a space extending in a diametrical planeperpendicular to the plane of the shelves and

